The scores of 12th graders on the Third International Mathematics and Science Study (TIMSS) were recently released. The test, given in 1995, shows American 12th-graders ranking at the very bottom in physics and advanced math (see figure). However, research psychologist and education writer Gerald Bracey says the results are deceptive.

Each country picked the students to take the advanced math portion based on the math they actually had taken. But for some reason, says Bracey, Americans who had only taken pre-calculus were given a test that presumed a knowledge of calculus.

• The overall international average score on the advanced math test was 501, while the average score of American students was 442, says Bracy.

• But among American students who had taken calculus, the average score was 492, and of those who took advanced-placement calculus, the average was 513.

Bracey contends that where the results test children of similar ages after taking similar courses, American 12th graders are "slightly above the international average if you adjust for just one variable: work."

• For reasons that aren't yet clear, says Bracey, youngsters who work at jobs about 15 hours a week do better on such tests than those who don't work.

• But students who work more than 25 hours a week do less well -- and 28 percent of the American 12th graders who took the TIMSS test said they worked more than 25 hours.

Furthermore, says Bracey, the students tested in some countries were two to four years older than their American counterparts.